ti: k3: drivers: Add Secure Proxy driver

Secure Proxy module manages hardware threads that are meant
for communication between the processor entities. Add support
for this here.

Signed-off-by: Andrew F. Davis <afd@ti.com>
diff --git a/plat/ti/k3/common/plat_common.mk b/plat/ti/k3/common/plat_common.mk
index 7cb6eb7..5f19127 100644
--- a/plat/ti/k3/common/plat_common.mk
+++ b/plat/ti/k3/common/plat_common.mk
@@ -36,6 +36,7 @@
 				-I${PLAT_PATH}/include			\
 				-Iinclude/plat/arm/common/		\
 				-Iinclude/plat/arm/common/aarch64/	\
+				-I${PLAT_PATH}/common/drivers/sec_proxy	\
 
 K3_CONSOLE_SOURCES	+=	\
 				drivers/console/aarch64/console.S	\
@@ -53,6 +54,9 @@
 				plat/common/plat_psci_common.c		\
 				${PLAT_PATH}/common/k3_psci.c		\
 
+K3_SEC_PROXY_SOURCES	+=	\
+				${PLAT_PATH}/common/drivers/sec_proxy/sec_proxy.c \
+
 PLAT_BL_COMMON_SOURCES	+=	\
 				plat/arm/common/arm_common.c		\
 				lib/cpus/aarch64/cortex_a53.S		\
@@ -65,3 +69,4 @@
 				${PLAT_PATH}/common/k3_topology.c	\
 				${K3_GIC_SOURCES}			\
 				${K3_PSCI_SOURCES}			\
+				${K3_SEC_PROXY_SOURCES}			\